Feature layer added to Feature Service does not show in AGOL

[MarkC1]

I've added a new feature layer to an existing feature service via the REST API (Add to Definition). The new feature layer gets added successfully and it is listed in the layers when viewing the service via the service URL. However, the layer does not appear in AGOL and I cannot access it. 

I've tested it with several existing feature services in my agol, by adding the exact same layer definition to multiple feature services. Some of for some of them it works perfectly but for others I get the above behaviour.  I have even tried to duplicate one of the existing layers in the feature services where I see this issue with no success.

Has anyone experienced this or can provide any help? I am guessing that there is something different about the layers it does not work on.

Edit: It seems to affect feature services originally published from Arcgis Pro

Example:

Point Layer 2 added via to existing layer via REST API. Visible at feature service URL but not showing up in AGOL

[Katie_Clark]

Chiming in here, I was working on this issue yesterday. Check out my response to this post here, I shared a snippet of my code in which I update the Item Details to reflect the layer change. Hope it helps.